When you get the time you should pull the hubs and bearings and repack them, use Mobil 1 synthetic grease, do it once right and you'll never have to do it again. Now back off the nut with the wrench until you feel that resistance dissipate, and one of the castellations on the nut lines up with the cotter pin hole. The key then is to hit the sweet spot between too much end play and not enough. Use one hand to turn the wheel slowly in its normal forward direction of travel, and tighten the hub nut to the correct torque with the other. You also should replace the spring-loaded seals that keep the wheel bearing grease from escaping out the backs of the hubs and dirt and water from intruding into the grease cavity. The reason is, the hub will expand when warm, reducing bearing clearance. Preload can be defined as a compression force applied to the bearings to secure them inside the wheel hub, remove all axial clearance and hold the assembly under load to keep the tapered rollers in the best position.
Some cars have a left-hand thread on nearside hub nuts, especially at the rear. Should stay cool to the touch or at the worst still be cool enough to clutch your hand around the spindle and hold onto it. Manufacturers of axles, suspensions, chassis and final equipment all have production areas to assemble wheel ends. To remove, lever up the tab with a screwdriver. © 2014 The Timken Company.
I know this is not orthodox but my dad always tightened them by hand, we always had utility trailers, boats, campers etc, he packed the bearings each year and tightened the bearings hand tight, fingers only, never ever not once had any problems and would trailer all over camping, fishing. This widely applied technique assumes that with reasonably uniform parts, the total deflection of any assembly will be consistent for a given applied load. In other words, once the gap is eliminated and the two surfaces are in contact, even a slight increase in torque applied to the nut will cause the force applied to the bearing to skyrocket, thus increasing the risk of excessive preload. Photo: Jim Park Somewhere between the thickness of a human hair and a sheet of paper. I've always treated mine the way I grew up packing and setting up automobile roller wheel bearings - clean, repack forcing grease through the rollers and cage, then tightening while spinning the wheel not just the hub, but with a wheel mounted until the bearing slowed the wheel to a stop in about one turn of freewheeling. On the other side of the spectrum, loosening the adjustment nut too much will cause excessive end play in the bearings, allowing a rocking motion that disrupts the even distribution of force along the rollers. It seldom is, according to Mike Beckett of M.
When tightening the adjusting nut or using a dial indicator to measure end play, always rotate or oscillate the rollers to be sure they are properly seated. If you are adjusting a wheel on which the works, release the handbrake. It wouldn't be too much of a stretch to suggest this isn't always the case. The amount of clearance between bearing rollers and raceways measured in this axial direction is called endplay. If you have to remove the wheel, loosen the wheel nuts before raising it. The hub nut may be a castellated nut retained by a split pin, or a plain nut under a castellated retainer held by a split pin.
Timken® is a registered trademark of The Timken Company. This method is capable of closely controlled setting ranges 0. To help, Timken has established an easily measurable three step adjustment procedure. Fleet maintenance shops and truck service centers aren't the only ones on the path to adopting preload settings for wheel end bearings. They torque the wheel nut on, back it off, torque it again, and then back off a quarter or half a turn of the nut. Tighten the inner nut to give the correct amount of play - just enough to let the wheel rotate freely - then bend down the tab.
If you back it off one-fourth of a turn, it will move away from the bearing about 0. Uneven wear of brake lining, for example, won't prevent the truck from stopping. It just means that all techniques available for wheel end bearing adjustment have the potential to achieve measurable settings somewhere in this wide endplay range. To ensure proper end play, a dial indicator should always be used. It may be a plain nut which has been locked by 'peening' it punching its outer edge to make the metal spread into a groove in the threaded axle end. The preponderance of the problems mentioned above should be a hint that bearing adjustment isn't always done correctly. We also use only one type of seal here.
Unfortunately, those symptoms take time to develop. You should be able to feel the barest hint of play. In production, the assembler measures initial bearing rolling torque preferably with a torque wrench and selects the shim size from the chart to obtain the desired bearing setting. Setting bearings to either preload or to endplay will have a significant impact on performance in wheel bearing arrangements in terms of bearing life, friction and proper functioning of the bearing. Compelling but anecdotal evidence suggests that wheel end tightness can affect fuel economy — sometimes significantly. Rotating or Oscillating the Bearing During adjustment, position the rollers tightly against the bearing cone inner race large rib.
A hydraulic shop press works best for installation, but with a certain amount of care it is possible to install the new race using a hammer and a punch. Also, spin the wheel and feel for roughness. And the force applied to the bearing with a torque wrench is exponential rather than linear. A technician establishes this relationship by testing several units under load, then prepares a chart showing what size shim to use for a given torque. To finish the job, fill the dust cap halfway with grease and tap it back on.
Chock the wheel on the opposite corner fore and aft. For example, our company offers five methods: Set-Right, Acro-Set, Projecta-Set, Torque-Set, and Clamp-Set. Install a shim of predetermined thickness based on testing previously described between carrier and housing to obtain the desired bearing setting. Adjusting non-driven bearings The bearing is adjusted by tightening the hub nut if it is too loose, or loosening the nut if it is too tight. While continuing to rotate this rotor, re-torque the nut, this time to 10 foot pounds.
Do I need to be watching for premature hub failure? Kenworth is adding the TruckTech+ Remote Diagnostics system as an option for its medium-duty conventional trucks. Because they are mounted in pairs, , their setting depends mostly on the location of one bearing row relative to the other on the shaft. It simplifies installation, cuts installation to just a few minutes, and sets a measured amount of preload on the bearings. You may have to pry out the seal first. When step one is complete, place the bottle cap type stamping over the adjusting nut and properly install and secure the cotter pin to prevent the nut from backing off.